Carbonaceous materials are versatile sorbents used in a wide range of applications, most particularly, for gas and liquid chromatography (LC). Two commercial carbon phases for LC—carbon clad zirconia (C/ZrO2) and porous graphitic carbon (Hypercarb)—among all the available reversed-phase materials show unique forms of chromatographic selectivity for polar and nonpolar compounds, as well as for structural isomers, and thus have been used to separate analytes that are not readily resolved by conventional reversed phases (e.g., alkyl silica phases).
The unique selectivity of C/ZrO2, combined with its mechanical strength, make it a promising choice for use in fast two-dimensional liquid chromatography (2DLC), but there is still a great need to improve its retentivity. A carbon phase on porous HPLC grade alumina has been reported and the resulting material (C/Al2O3) showed 4-5-fold higher retentivity than did C/ZrO2, while maintaining the unique selectivity of a carbon-like adsorbent. However, the further development of C/Al2O3 has been limited by the paucity of available varieties of HPLC grade porous aluminas.
New carbonaceous materials are needed as sorbents for chromatography.